Method and apparatus for limiting acidic corrosion and contamination in fuel delivery systems

ABSTRACT

A method and apparatus are provided for controlling a fuel delivery system to limit acidic corrosion. An exemplary control system includes a controller, at least one monitor, an output, and a remediation system. The monitor of the control system may collect and analyze data indicative of a corrosive environment in the fuel delivery system. The output of the control system may automatically warn an operator of the fueling station of the corrosive environment so that the operator can take preventative or corrective action. The remediation system of the control system may take at least one corrective action to remediate the corrosive environment in the fuel delivery system.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 16/557,363 filed Aug. 30, 2019, which claims thebenefit of U.S. Provisional Patent Application Ser. No. 62/814,428 filedMar. 6, 2019 and is a continuation-in-part of U.S. patent applicationSer. No. 15/914,535 filed Mar. 7, 2018, which claims priority to U.S.Provisional Patent Application Ser. No. 62/468,033 filed Mar. 7, 2017,U.S. Provisional Patent Application Ser. No. 62/509,506 filed May 22,2017, U.S. Provisional Patent Application Ser. No. 62/520,891 filed Jun.16, 2017, and U.S. Provisional Patent Application Ser. No. 62/563,596filed Sep. 26, 2017. The disclosures of all of the foregoingapplications are hereby expressly incorporated by reference herein intheir entireties.

FIELD OF THE DISCLOSURE

The present disclosure relates to controlling fuel delivery systems and,in particular, to a method and apparatus for controlling fuel deliverysystems to limit acidic corrosion, and/or to limit the accumulation ofwater and particulate matter in stored fuel.

BACKGROUND OF THE DISCLOSURE

A fuel delivery system typically includes one or more undergroundstorage tanks that store various fuel products and one or more fueldispensers that dispense the fuel products to consumers. The undergroundstorage tanks may be coupled to the fuel dispensers via correspondingunderground fuel delivery lines.

In the context of an automobile fuel delivery system, for example, thefuel products may be delivered to consumers' automobiles. In suchsystems, the fuel products may contain a blend of gasoline and alcohol,specifically ethanol. Blends having about 2.5 vol. % ethanol (“E-2.5”),5 vol. % ethanol (“E-5”), 10 vol. % ethanol (“E-10”), or more, in somecases up to 85 vol. % ethanol (“E-85”), are now available as fuel forcars and trucks in the United States and abroad. Other fuel productsinclude diesel and biodiesel, for example.

Sumps (i.e., pits) may be provided around the equipment of the fueldelivery system. Such sumps may trap liquids and vapors to preventenvironmental releases. Also, such sumps may facilitate access andrepairs to the equipment. Sumps may be provided in various locationsthroughout the fuel delivery system. For example, dispenser sumps may belocated beneath the fuel dispensers to provide access to piping,connectors, valves, and other equipment located beneath the fueldispensers. As another example, turbine sumps may be located above theunderground storage tanks to provide access to turbine pump heads,piping, leak detectors, electrical wiring, and other equipment locatedabove the underground storage tanks.

Underground storage tanks and sumps may experience premature corrosion.Efforts have been made to control such corrosion with fuel additives,such as biocides and corrosion inhibitors. However, the fuel additivesmay be ineffective against certain microbial species, become depletedover time, and cause fouling, for example. Efforts have also been madeto control such corrosion with rigorous and time-consuming watermaintenance practices, which are typically disfavored by retail fuelingstation operators.

Water and/or particulate matter sometimes also contaminates the fuelstored in underground storage tanks. Because these contaminants aregenerally heavier than the fuel product itself, any water or particulatematter found in the storage tank is generally confined to a “layer” offuel mixed with contaminants at bottom of the tank. Because dispensationof these contaminants may have adverse effects on vehicles or otherend-use applications, efforts have been made to timely detect andremediate such contaminants.

SUMMARY

The present disclosure relates to a method and apparatus for controllinga fuel delivery system to limit acidic corrosion. An exemplary controlsystem includes a controller, at least one monitor, an output, and aremediation system. The monitor of the control system may collect andanalyze data indicative of a corrosive environment in the fuel deliverysystem. The output of the control system may automatically warn anoperator of the fueling station of the corrosive environment so that theoperator can take preventative or corrective action. The remediationsystem of the control system may take at least one corrective action toremediate the corrosive environment in the fuel delivery system.

The present disclosure further relates to a method and apparatus forfiltration of fuel contained in a storage tank, in which activation of afuel dispensation pump concurrently activates a filtration system. Inparticular, a portion of pressurized fuel delivered by the dispensationpump is diverted to an eductor designed to create a vacuum by theventuri effect. This vacuum draws fluid from the bottom of the storagetank, at a point lower than the intake for the dispensation pump so thatany water or particulate matter at the bottom of the storage tank isdelivered to the eductor before it can reach the dispensation pumpintake. The eductor delivers a mix of the diverted fuel and thetank-bottom fluid to a filter, where any entrained particulate matter orwater is filtered out and removed from the product stream. Clean,filtered fuel is then delivered back to the storage tank.

According to an embodiment of the present disclosure, a fuel deliverysystem is provided including a storage tank containing a fuel product, afuel delivery line in communication with the storage tank, at least onemonitor that collects data indicative of a corrosive environment in thefuel delivery system, a controller in communication with the at leastone monitor to receive collected data from the at least one monitor, anda remediation system configured to take at least one corrective actionto remediate the corrosive environment when activated by the controllerin response to the collected data.

According to another embodiment of the present disclosure, a fueldelivery system is provided including a storage tank containing a fuelproduct, a fuel delivery line in communication with the storage tank, amonitor including a light source, a corrosive target material exposed toa corrosive environment in the fuel delivery system, and a detectorconfigured to detect light from the light source through the targetmaterial, and a controller in communication with the monitor.

According to yet another embodiment of the present disclosure, a fueldelivery system is provided including a storage tank containing a fuelproduct, a sump, a pump having a first portion positioned in the sumpand a second portion positioned in the storage tank, and a waterfiltration system. The water filtration system includes a water filterpositioned in the sump and configured to separate the fuel product intoa filtered fuel product and a separated water product, a fuel inletpassageway in fluid communication with the storage tank and the waterfilter via the pump to direct the fuel product to the water filter, afuel return passageway in fluid communication with the water filter andthe storage tank to return the filtered fuel product to the storagetank, and a water removal passageway in fluid communication with thewater filter to drain the separated water product from the water filter.

According to still another embodiment of the present disclosure, a fueldelivery system is provided including a water filtration system. Thewater filtration system includes a filter configured to separate a fuelproduct into a filtered fuel product and a separated water product, aneductor configured to receive a flow of fuel from a fuel delivery pumpand send the flow of fuel to the filter, and a vacuum port on theeductor configured to be operably connected to a source of contaminatedfuel, such that the vacuum port draws the contaminated fuel into theflow of fuel through the eductor and delivers a mixture of fuel andcontaminated fuel to the filter.

According to still another embodiment of the present disclosure, a fueldelivery system is disclosed including a storage tank containing a fuelproduct, a dispenser, a water filter, a fuel uptake line in fluidcommunication with the storage tank and the dispenser to deliver thefuel product to the dispenser, a filtration uptake line in fluidcommunication with the storage tank and the water filter to deliver thefuel product to the water filter, the water filter being configured toseparate the fuel product into a filtered fuel product and a separatedwater product, a fuel return passageway in fluid communication with thewater filter and the storage tank to return the filtered fuel product tothe storage tank, and a water removal passageway in fluid communicationwith the water filter to drain the separated water product from thewater filter.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of thisdisclosure, and the manner of attaining them, will become more apparentand the invention itself will be better understood by reference to thefollowing description of embodiments of the invention taken inconjunction with the accompanying drawings, wherein:

FIG. 1 depicts an exemplary fuel delivery system of the presentdisclosure showing above ground components, such as a fuel dispenser,and below ground components, such as a storage tank containing a fuelproduct, a fuel delivery line, a turbine sump, and a dispenser sump;

FIG. 2 is a cross-sectional view of the storage tank and the turbinesump of FIG. 1 ;

FIG. 3 is a schematic view of an exemplary control system of the presentdisclosure, the control system including a controller, at least onemonitor, an output, and a remediation system;

FIG. 4 is a schematic view of a first exemplary electrical monitor foruse in the control system of FIG. 3 ;

FIG. 5 is a schematic view of a second exemplary electrical monitor foruse in the control system of FIG. 3 ;

FIG. 6 is a schematic view of a third exemplary optical monitor for usein the control system of FIG. 3 ;

FIG. 7 includes photographs of the corrosive samples tested in Example1;

FIG. 8 is a graphical representation of the relative transmitted lightintensity through each sample of Example 1 over time;

FIG. 9 is a graphical representation of the normalized transmitted lightintensity through each sample of Example 1 over time;

FIG. 10 is a graphical representation of the transmitted light intensitythrough the corrosive sample tested in Example 2 over time;

FIG. 11 is a perspective view of the turbine sump having a waterfiltration system;

FIG. 12 is a perspective view of the turbine sump having a waterfiltration system similar to FIG. 11 and also including a water storagetank;

FIG. 13 shows an exemplary method for operating the water filtrationsystem;

FIG. 14 is a schematic view of another exemplary water filtration systemutilizing continuous filtration by eduction;

FIG. 15 is an enlarged portion of the schematic view of FIG. 14 ,illustrating the components of the water filtration system;

FIG. 16 is a perspective view of another exemplary optical monitorincluding an upper housing with a light source and an optical detectorand a lower housing with a corrosive target material and a reflectivesurface;

FIG. 17 is an exploded perspective view of the lower housing and thecorrosive target material of FIG. 16 ;

FIG. 18 is a top plan view of the lower housing and the corrosive targetmaterial of FIG. 16 ;

FIG. 19 is a partial cross-sectional view of the optical monitor of FIG.16 ;

FIG. 20 is a graphical representation of the relative humidity andtemperature over time in a turbine sump with a desiccant; and

FIG. 21 is a schematic view of another exemplary water filtration systemutilizing continuous filtration by eduction;

FIG. 22 is an enlarged portion of the schematic view of FIG. 21 ,illustrating the components of the water filtration system;

FIG. 23 is a perspective view of yet another exemplary water filtrationsystem utilizing continuous filtration by eduction;

FIG. 24A is side elevation, section and partial cutaway view of thewater filtration system of FIG. 23 ;

FIG. 24B is side elevation, enlarged view of a portion of the waterfiltration system of FIG. 24A;

FIG. 25 is a side elevation, section view of a portion of the waterfiltration system of FIG. 23 , illustrating the water filter at partialwater capacity;

FIG. 26 is another side elevation, section view of a portion of thewater filtration system of FIG. 23 , illustrating the water filter atfull water capacity; and

FIG. 27 is a perspective view of an automatic shutoff valve used in thewater filter shown in FIGS. 23-26 .

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate exemplary embodiments of the invention and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

An exemplary fuel delivery system 10 is shown in FIG. 1 . Fuel deliverysystem 10 includes a fuel dispenser 12 for dispensing a liquid fuelproduct 14 from a liquid storage tank 16 to consumers. Each storage tank16 is fluidly coupled to one or more dispensers 12 via a correspondingfuel delivery line 18. Storage tank 16 and delivery line 18 areillustratively positioned underground, but it is also within the scopeof the present disclosure that storage tank 16 and/or delivery line 18may be positioned above ground.

Fuel delivery system 10 of FIG. 1 also includes a pump 20 to draw fuelproduct 14 from storage tank 16 and to convey fuel product 14 throughdelivery line 18 to dispenser 12. Pump 20 is illustratively asubmersible turbine pump (“STP”) having a turbine pump head 22 locatedabove storage tank 16 and a submersible motor 24 located inside storagetank 16. However, it is within the scope of the present disclosure thatother types of pumps may be used to transport fuel product 14 throughfuel delivery system 10.

Fuel delivery system 10 of FIG. 1 further includes various undergroundsumps (i.e., pits). A first, dispenser sump 30 is provided beneathdispenser 12 to protect and provide access to piping (e.g., deliveryline 18), connectors, valves, and other equipment located therein, andto contain any materials that may be released beneath dispenser 12. Asecond, turbine sump 32, which is also shown in FIG. 2 , is providedabove storage tank 16 to protect and provide access to pump 20, piping(e.g., delivery line 18), leak detector 34, electrical wiring 36, andother equipment located therein. Turbine sump 32 is illustrativelycapped with an underground lid 38 and a ground-level manhole cover 39,which protect the equipment inside turbine sump 32 when installed andallow access to the equipment inside turbine sump 32 when removed.

According to an exemplary embodiment of the present disclosure, fueldelivery system 10 is an automobile fuel delivery system. In thisembodiment, fuel product 14 may be a gasoline/ethanol blend that isdelivered to consumers' automobiles, for example. The concentration ofethanol in the gasoline/ethanol blended fuel product 14 may vary from 0vol. % to 15 vol. % or more. For example, fuel product 14 may containabout 2.5 vol. % ethanol (“E-2.5”), about 5 vol. % ethanol (“E-5”),about 7.5 vol. % ethanol (“E-7.5”), about 10 vol. % ethanol (“E-10”),about 15 vol. % ethanol (“E-15”), or more, in some cases up to about 85vol. % ethanol (“E-85”). As discussed in U.S. Publication No.2012/0261437, the disclosure of which is expressly incorporated hereinby reference in its entirety, the ethanol may attract water into thegasoline/ethanol blended fuel product 14. The water in fuel product 14may be present in a dissolved state, an emulsified state, or a freewater state. Eventually, the water may also cause phase separation offuel product 14.

In addition to being present in storage tank 16 as part of thegasoline/ethanol blended fuel product 14, ethanol may find its way intoother locations of fuel delivery system 10 in a vapor or liquid state,including dispenser sump 30 and turbine sump 32. In the event of a fluidleak from dispenser 12, for example, some of the gasoline/ethanolblended fuel product 14 may drip from dispenser 12 into dispenser sump30 in a liquid state. Also, in the event of a vapor leak from storagetank 16, vapor in the ullage of storage tank 16 may escape from storagetank 16 and travel into turbine sump 32. In certain situations, turbinesump 32 and/or components contained therein (e.g., metal fittings, metalvalves, metal plates) may be sufficiently cool in temperature tocondense the ethanol vapor back into a liquid state in turbine sump 32.Along with ethanol, water from the surrounding soil, fuel product 14, oranother source may also find its way into sumps 30, 32 in a vapor orliquid state, such as by dripping into sumps 30, 32 in a liquid state orby evaporating and then condensing in sumps 30, 32. Ethanol and/or waterleaks into sumps 30, 32 may occur through various connection points insumps 30, 32, for example. Ethanol and/or water may escape fromventilated sumps 30, 32 but may become trapped in unventilated sumps 30,32.

In the presence of certain bacteria and water, ethanol that is presentin fuel delivery system 10 may be oxidized to produce acetate, accordingto Reaction I below.CH₃CH₂OH+H₂O→CH₃COO⁻+H⁺+2H₂  (I)

The acetate may then be protonated to produce acetic acid, according toReaction II below.CH₃COO⁻H⁺→CH₃COOH  (II)

The conversion of ethanol to acetic acid may also occur in the presenceof oxygen according to Reaction III below.2CH₃CH₂OH+O₂→2CH₃COOH+2H₂O  (III)

Acetic acid producing bacteria or AAB may produce acetate and aceticacid by a metabolic fermentation process, which is used commercially toproduce vinegar, for example. Acetic acid producing bacteria generallybelong to the Acetobacteraceae family, which includes the generaAcetobacter, Gluconobacter, and Gluconacetobacter. Acetic acid producingbacteria are very prevalent in nature and may be present in the soilaround fuel delivery system 10, for example. Such bacteria may findtheir way into sumps 30, 32 to drive Reactions I-III above, such as whensoil or debris falls into sumps 30, 32 or when rainwater seeps intosumps 30, 32.

The products of Reactions I-III above may reach equilibrium in sumps 30,32, with some of the acetate and acetic acid dissolving into liquidwater that is present in sumps 30, 32, and some of the acetate andacetic acid volatilizing into a vapor state. In general, the amountacetate or acetic acid that is present in the vapor state isproportional to the amount of acetate or acetic acid that is present inthe liquid state (i.e, the more acetate or acetic acid that is presentin the vapor state, the more acetate or acetic acid that is present inthe liquid state).

Even though acetic acid is classified as a weak acid, it may becorrosive to fuel delivery system 10, especially at high concentrations.For example, the acetic acid may react to deposit metal oxides (e.g.,rust) or metal acetates on metallic fittings of fuel delivery system 10.Because Reactions I-III are microbiologically-influenced reactions,these deposits in fuel delivery system 10 may be tubular or globular inshape.

To limit corrosion in fuel delivery system 10, a control system 100 anda corresponding monitoring method are provided herein. As shown in FIG.3 , the illustrative control system 100 includes controller 102, one ormore monitors 104 in communication with controller 102, output 106 incommunication with controller 102, and remediation system 108 incommunication with controller 102, each of which is described furtherbelow.

Controller 102 of control system 100 illustratively includes amicroprocessor 110 (e.g., a central processing unit (CPU)) and anassociated memory 112. Controller 102 may be any type of computingdevice capable of accessing a computer-readable medium having one ormore sets of instructions (e.g., software code) stored therein andexecuting the instructions to perform one or more of the sequences,methodologies, procedures, or functions described herein. In general,controller 102 may access and execute the instructions to collect, sort,and/or analyze data from monitor 104, determine an appropriate response,and communicate the response to output 106 and/or remediation system108. Controller 102 is not limited to being a single computing device,but rather may be a collection of computing devices (e.g., a collectionof computing devices accessible over a network) which together executethe instructions. The instructions and a suitable operating system forexecuting the instructions may reside within memory 112 of controller102, for example. Memory 112 may also be configured to store real-timeand historical data and measurements from monitors 104, as well asreference data. Memory 112 may store information in databasearrangements, such as arrays and look-up tables.

Controller 102 of control system 100 may be part of a larger controllerthat controls the rest of fuel delivery system 10. In this embodiment,controller 102 may be capable of operating and communicating with othercomponents of fuel delivery system 10, such as dispenser 12 (FIG. 1 ),pump 20 (FIG. 2 ), and leak detector 34 (FIG. 2 ), for example. Anexemplary controller 102 is the TS-550 Evo® Fuel Management Systemavailable from Franklin Fueling Systems Inc. of Madison, Wis.

Monitor 104 of control system 100 is configured to automatically androutinely collect data indicative of a corrosive environment in fueldelivery system 10. In operation, monitor 104 may draw in a liquid orvapor sample from fuel delivery system 10 and directly test the sampleor test a target material that has been exposed to the sample, forexample. In certain embodiments, monitor 104 operates continuously,collecting samples and measuring data approximately once every second orminute, for example. Monitor 104 is also configured to communicate thecollected data to controller 102. In certain embodiments, monitor 104manipulates the data before sending the data to controller 102. In otherembodiments, monitor 104 sends the data to controller 102 in raw formfor manipulation by controller 102. The illustrative monitor 104 iswired to controller 102, but it is also within the scope of the presentdisclosure that monitor 104 may communicate wirelessly (e.g., via aninternet network) with controller 102.

Depending on the type of data being collected by each monitor 104, thelocation of each monitor 104 in fuel delivery system 10 may vary.Returning to the illustrated embodiment of FIG. 2 , for example, monitor104′ is positioned in the liquid space (e.g, middle or bottom) ofstorage tank 16 to collect data regarding the liquid fuel product 14 instorage tank 16, monitor 104″ is positioned in the ullage or vapor space(i.e., top) of storage tank 16 to collect data regarding any vaporspresent in storage tank 16, monitor 104′″ is positioned in the liquidspace (i.e., bottom) of turbine sump 32 to collect data regarding anyliquids present in turbine sump 32, and monitor 104″ is positioned inthe vapor space (i.e., top) of turbine sump 32 to collect data regardingany vapors present in turbine sump 32. Monitor 104 may be positioned inother suitable locations of fuel delivery system 10, including deliveryline 18 and dispenser sump 30 (FIG. 1 ), for example. Various monitors104 for use in control system 100 of FIG. 3 are discussed further below.

Output 106 of control system 100 may be capable of communicating analarm or warning from controller 102 to an operator. Output 106 mayinclude a visual indication device (e.g., a gauge, a display screen,lights, a printer), an audio indication device (e.g., a speaker, anaudible alarm), a tactile indication device, or another suitable devicefor communicating information to the operator, as well as combinationsthereof. Controller 102 may transmit information to output 106 inreal-time, or controller 102 may store information in memory 112 forsubsequent transmission or download to output 106.

Remediation system 108 of control system 100 may be capable of taking atleast one corrective action to remediate the corrosive environment infuel delivery system 10. Various embodiments of remediation system 108are described below.

The illustrative output 106 and remediation system 108 are wired tocontroller 102, but it is also within the scope of the presentdisclosure that output 106 and/or remediation system 108 may communicatewirelessly (e.g., via an internet network) with controller 102. Forexample, to facilitate communication between output 106 and theoperator, output 106 may be located in the operator's control room oroffice.

In operation, and as discussed above, controller 102 collects, sorts,and/or analyzes data from monitor 104, determines an appropriateresponse, and communicates the response to output 106 and/or remediationsystem 108. According to an exemplary embodiment of the presentdisclosure, output 106 warns the operator of a corrosive environment infuel delivery system 10 and/or remediation system 108 takes correctiveaction before the occurrence of any corrosion or any significantcorrosion in fuel delivery system 10. In this embodiment, corrosion maybe prevented or minimized. It is also within the scope of the presentdisclosure that output 106 may alert the operator to the occurrence ofcorrosion in fuel delivery system 10 and/or remediation system 108 maytake corrective action to at least avoid further corrosion.

Various factors may influence whether controller 102 issues an alarm orwarning from output 106 that a corrosive environment is present in fueldelivery system 10 or becoming more likely to develop. Similar factorsmay also influence whether controller 102 instructs remediation system108 to take corrective action in response to the corrosive environment.As discussed further below, these factors may be evaluated based on dataobtained from one or more monitors 104.

One factor indicative of a corrosive environment includes theconcentration of acidic molecules in fuel delivery system 10, withcontroller 102 issuing an alarm or warning from output 106 and/oractivating remediation system 108 when the measured concentration ofacidic molecules in fuel delivery system 10 exceeds an acceptableconcentration of acidic molecules in fuel delivery system 10. Theconcentration may be expressed in various units. For example, controller102 may activate output 106 and/or remediation system 108 when themeasured concentration of acidic molecules in fuel delivery system 10exceeds 25 ppm, 50 ppm, 100 ppm, 150 ppm, 200 ppm, or more, or when themeasured concentration of acidic molecules in fuel delivery system 10exceeds 25 mg/L, 50 mg/L, 100 mg/L, 150 mg/L, 200 mg/L, or more. At orbeneath the acceptable concentration, corrosion in fuel delivery system10 may be limited. Controller 102 may also issue an alarm or warningfrom output 106 and/or activate remediation system 108 when theconcentration of acidic molecules increases at an undesirably high rate.

Another factor indicative of a corrosive environment includes theconcentration of hydrogen ions in fuel delivery system 10, withcontroller 102 issuing an alarm or warning from output 106 and/oractivating remediation system 108 when the measured concentration ofhydrogen ions in fuel delivery system 10 exceeds an acceptableconcentration of hydrogen ions in fuel delivery system 10. For example,controller 102 may activate output 106 and/or remediation system 108when the hydrogen ion concentration causes the pH in fuel deliverysystem 10 to drop below 5, 4, 3, or 2, for example. Within theacceptable pH range, corrosion in fuel delivery system 10 may belimited. Controller 102 may also issue an alarm or warning from output106 and/or activate remediation system 108 when the concentration ofhydrogen ions increases at an undesirably high rate.

Yet another factor indicative of a corrosive environment includes theconcentration of bacteria in fuel delivery system 10, with controller102 issuing an alarm or warning from output 106 and/or activatingremediation system 108 when the measured concentration of bacteria infuel delivery system 10 exceeds an acceptable concentration of bacteriain fuel delivery system 10. At or beneath the acceptable concentration,the production of corrosive materials in fuel delivery system 10 may belimited. Controller 102 may also issue an alarm or warning from output106 and/or activate remediation system 108 when the concentration ofbacteria increases at an undesirably high rate.

Yet another factor indicative of a corrosive environment includes theconcentration of water in fuel delivery system 10, with controller 102issuing an alarm or warning from output 106 and/or activatingremediation system 108 when the measured concentration of water in fueldelivery system 10 exceeds an acceptable concentration of water in fueldelivery system 10. At or beneath the acceptable concentration, theproduction of corrosive materials in fuel delivery system 10 may belimited. Controller 102 may also issue an alarm or warning from output106 and/or activate remediation system 108 when the concentration ofwater increases at an undesirably high rate. The water may be present inliquid and/or vapor form.

Controller 102 may be programmed to progressively vary the alarm orwarning communication from output 106 as the risk of corrosion in fueldelivery system 10 increases. For example, controller 102 mayautomatically trigger: a minor alarm (e.g., a blinking light) whenmonitor 104 detects a relatively low acid concentration level (e.g., 5ppm) in fuel delivery system 10 or a relatively steady acidconcentration level over time; a moderate alarm (e.g., an audible alarm)when monitor 104 detects a moderate acid concentration level (e.g., 10ppm) in fuel delivery system 10 or a moderate increase in the acidconcentration level over time; and a severe alarm (e.g., a telephonecall or an e-mail to the gas station operator) when monitor 104 detectsa relatively high acid concentration level (e.g., 25 ppm) in fueldelivery system 10 or a relatively high increase in the acidconcentration level over time.

The alarm or warning communication from output 106 allows the operatorto manually take precautionary or corrective measures to limit corrosionof fuel delivery system 10. For example, if an alarm or warningcommunication is signaled from turbine sump 32 (FIG. 2 ), the operatormay remove manhole cover 39 and lid 38 to clean turbine sump 32, whichmay involve removing bacteria and potentially corrosive liquids andvapors from turbine sump 32. As another example, the operator mayinspect fuel delivery system 10 for a liquid leak or a vapor leak thatallowed ethanol and/or its acidic reaction products to enter turbinesump 32 in the first place.

Even if no immediate action is required, the alarm or warningcommunication from output 106 may allow the operator to better plan forand predict when such action may become necessary. For example, theminor alarm from output 106 may indicate that service should beperformed within about 2 months, the moderate alarm from output 106 mayindicate that service should be performed within about 1 month, and thesevere alarm from output 106 may indicate that service should beperformed within about 1 week.

As discussed above, control system 100 includes one or more monitors 104that collect data indicative of a corrosive environment in fuel deliverysystem 10. Each monitor 104 may vary in the type of data that iscollected, the type of sample that is evaluated for testing, and thelocation of the sample that is evaluated for testing, as exemplifiedbelow.

In one embodiment, monitor 104 collects electrical data indicative of acorrosive environment in fuel delivery system 10. An exemplaryelectrical monitor 104 a is shown in FIG. 4 and includes an energysource 120, a corrosive target material 122 that is exposed to a liquidor vapor sample S from fuel delivery system 10, and a sensor 124. Toenhance the longevity of monitor 104 a, energy source 120 and/or sensor124 may be protected from any corrosive environment in fuel deliverysystem 10, unlike target material 122. Target material 122 may bedesigned to corrode before the equipment of fuel delivery system 10corrodes. Target material 122 may be constructed of or coated with amaterial that is susceptible to acidic corrosion, such as copper or lowcarbon steel. Also, target material 122 may be relatively thin or smallin size compared to the equipment of fuel delivery system 10 such thateven a small amount of corrosion will impact the structural integrity oftarget material 122. For example, target material 122 may be in the formof a thin film or wire.

In use, energy source 120 directs an electrical current through targetmaterial 122. When target material 122 is intact, sensor 124 senses theelectrical current traveling through target material 122. However, whenexposure to sample S causes target material 122 to corrode andpotentially break, sensor 124 will sense a decreased electrical current,or no current, traveling through target material 122. It is also withinthe scope of the present disclosure that the corrosion and/or breakageof target material 122 may be detected visually, such as by using acamera as sensor 124. First monitor 104 a may share the data collectedby sensor 124 with controller 102 (FIG. 3 ) to signal a corrosiveenvironment in fuel delivery system 10 when the electrical currentreaches an undesirable level or changes at an undesirable rate, forexample. After use, the corroded target material 122 may be discardedand replaced.

Another exemplary electrical monitor 104 b is shown in FIG. 5 andincludes opposing, charged metal plates 130. The electrical monitor 104b operates by measuring electrical properties (e.g., capacitance,impedence) of a liquid or vapor sample S that has been withdrawn fromfuel delivery system 10. In the case of a capacitance monitor 104 b, forexample, the sample S is directed between plates 130. Knowing the sizeof plates 130 and the distance between plates 130, the dielectricconstant of the sample S may be calculated. As the quantity of acetate,acetic acid, and/or water in the sample S varies, the dielectricconstant of the sample S may also vary. The electrical monitor 104 b mayshare the collected data with controller 102 (FIG. 3 ) to signal acorrosive environment in fuel delivery system 10 when the dielectricconstant reaches an undesirable level or changes at an undesirable rate,for example. One example of electrical monitor 104 b is a water contentmonitor that may be used to monitor the water content of fuel product 14or another sample S from fuel delivery system 10. An exemplary watercontent monitor is the ICM-W monitor available from MP Filtri, whichuses a capacitive sensor to measure the relative humidity (RH) of thetested fluid. As the RH increases toward a saturation point, the waterin the fluid may transition from a dissolved state, to an emulsifiedstate, to a free water state. Other exemplary water content monitors aredescribed in the above-incorporated U.S. Publication No. 2012/0261437.Another example of electrical monitor 104 b is a humidity sensor thatmay be used to monitor the humidity in the vapor space of storage tank16 and/or turbine sump 32.

In another embodiment, monitor 104 collects elecrochemical dataindicative of a corrosive environment in fuel delivery system 10. Anexemplary electrochemical monitor (not shown) performs potentiometrictitration of a sample that has been withdrawn from fuel delivery system10. A suitable potentiometric titration device includes anelectrochemical cell with an indicator electrode and a referenceelectrode that maintains a consistent electrical potential. As a titrantis added to the sample and the electrodes interact with the sample, theelectric potential across the sample is measured. Potentiometric orchronopotentiometric sensors, which may be based on solid-statereversible oxide films, such as that of iridium, may be used to measurepotential in the cell. As the concentration of acetate or acetic acid inthe sample varies, the potential may also vary. The potentiometrictitration device may share the collected data with controller 102 (FIG.3 ) to signal a corrosive environment in fuel delivery system 10 whenthe potential reaches an undesirable level or changes at an undesirablerate, for example. An electrochemical monitor may also operate byexposing the sample to an electrode, performing a reduction-oxidationwith the sample at the electrode, and measuring the resulting current,for example.

In yet another embodiment, monitor 104 collects optical data indicativeof a corrosive environment in fuel delivery system 10. An exemplaryoptical monitor 104 c is shown in FIG. 6 and includes a light source 140(e.g., LED, laser), an optical target material 142 that is exposed to aliquid or vapor sample S from fuel delivery system 10, and an opticaldetector 144 (e.g., photosensor, camera). To enhance the safety ofmonitor 104 c, light source 140 may be a low-energy and high-outputdevice, such as a green LED. Target material 142 may be constructed ofor coated with a material (e.g., an acid-sensitive polymer) that changesoptical properties (e.g., color, transmitted light intensity) in thepresence of the sample S.

Optical monitor 104 c may enable real-time, continuous monitoring offuel delivery system 10 by installing light source 140, target material142, and detector 144 together in fuel delivery system 10. To enhancethe longevity of this real-time monitor 104 c, light source 140 and/ordetector 144 may be protected from any corrosive environment in fueldelivery system 10, unlike target material 142. For example, lightsource 140 and/or detector 144 may be contained in a sealed housing,whereas target material 142 may be exposed to the surroundingenvironment in fuel delivery system 10.

Alternatively, optical monitor 104 c may enable manual, periodicmonitoring of fuel delivery system 10. During exposure, target material142 may be installed alone in fuel delivery system 10. During testing,target material 142 may be periodically removed from fuel deliverysystem 10 and positioned between light source 140 and detector 144. In afirst embodiment of the manual monitor 104 c, light source 140 anddetector 144 may be sold as a stand-alone, hand-held unit that isconfigured to receive the removed target material 142. In a secondembodiment of the manual monitor 104 c, light source 140 may be soldalong with a software application to convert the operator's ownsmartphone or mobile device into a suitable detecor 144. Detector 144 ofmonitor 104 c may transmit information to controller 102 (FIG. 3 ) inreal-time or store information in memory for subsequent transmission ordownload.

One suitable target material 142 includes a pH indicator that changescolor when target material 142 is exposed to an acidic pH with H⁺protons, such as a pH less than about 5, 4, 3, or 2, for example. Theoptical properties of target material 142 may be configured to changebefore the equipment of fuel delivery system 10 corrodes. Detector 144may use optical fibers as the sensing element (i.e., intrinsic sensors)or as a means of relaying signals to a remote sensing element (i.e.,extrinsic sensors).

In use, light source 140 directs a beam of light toward target material142. Before target material 142 changes color, for example, detector 144may detect a certain reflection, transmission (i.e., spectrophotometry),absorbtion (i.e., densitometry), and/or refraction of the the light beamfrom target material 142. However, after target material 142 changescolor, detector 144 will detect a different reflection, transmission,absorbtion, and/or refraction of the the light beam. It is also withinthe scope of the present disclosure that the changes in target material142 may be detected visually, such as by using a camera (e.g., asmartphone camera) as detector 144. Third monitor 104 c may share thedata collected by detector 144 with controller 102 (FIG. 3 ) to signal acorrosive environment in fuel delivery system 10 when the color reachesan undesirable level or changes at an undesirable rate, for example.

Another suitable target material 142 includes a sacrificial, corrosivematerial that corrodes (e.g., rusts) when exposed to a corrosiveenvironment in fuel delivery system 10. For example, the corrosivetarget material 142 may include copper or low carbon steel. Thecorrosive target material 142 may have a high surface area to volumeratio to provide detector 144 with a large and reliable sample size. Forexample, as shown in FIG. 6 , the corrosive target material 142 may bein the form of a woven mesh or perforated sheet having a large pluralityof pores 143.

In use, light source 140 directs a beam of light along an axis A towardthe corrosive target material 142. Before target material 142 corrodes,detector 144 may detect a certain amount of light that passes from thelight source 140 and through the open pores 143 of the illuminatedtarget material 142 along the same axis A. However, as target material142 corrodes, the material may visibly swell as rust accumulates in andaround some or all of the pores 143. This accumulating rust may obstructor prevent light from traveling through pores 143, so detector 144(e.g., a photodiode) will detect a decreasing amount of light throughthe corroding target material 142. It is also within the scope of thepresent disclosure that the changes in target material 142 may bedetected visually, such as by using a camera or another suitable imagingdevice as detector 144. Detector 144 may capture an image of theilluminated target material 142 and then evaluate the image (e.g.,pixels of the image) for transmitted light intensity, specific lightpatterns, etc. As discussed above, third monitor 104 c may share thedata collected by detector 144 with controller 102 (FIG. 3 ) to signal acorrosive environment in fuel delivery system 10 when the transmittedlight intensity reaches an undesirable level or changes at anundesirable rate, for example. After use, the corroded target material142 may be discarded and replaced.

Another exemplary optical monitor 104 c′ is shown in FIGS. 16-19 .Optical monitor 104 c′ of FIGS. 16-19 is similar to optical monitor 104c of FIG. 6 and includes several components and features in common withoptical monitor 104 c as indicated by the use of common referencenumbers between optical monitors 104 c, 104 c′, including a light source140′, a corrosive target material 142′, and an optical detector 144′.Optical monitor 104 c′ may be mounted in the vapor space of storage tank16 and/or turbine sump 32 of fuel delivery system 10 (FIG. 2 ).

The illustrative optical monitor 104 c′ is generally cylindrical inshape and has a longitudinal axis L. In the illustrated embodiment ofFIG. 19 , light source 140′ and target material 142′ are located on afirst side of axis L (illustratively the right side of axis L), andoptical detector 144′ is located on a second side of axis L(illustratively the left side of axis L). Light source 140′ and opticaldetector 144′ are substantially coplanar and are located above targetmaterial 142′. The illustrative target material 142′ is a L-shaped meshsheet, with a vertical portion 145 a′ of target material 142′ extendingparallel to axis L and a horizontal portion 145 b′ of target material142′ extending perpendicular to axis L.

The illustrative optical monitor 104 c′ includes a reflective surface500′ positioned downstream of light source 140′ and upstream of opticaldetector 144′, wherein the reflective surface 500′ is configured toreflect incident light from light source 140′ toward optical detector144′. In the illustrated embodiment of FIG. 19 , the incident light fromlight source 140′ travels downward and inward toward axis L along afirst axis A₁ toward reflective surface 500′, and then the reflectedlight from reflective surface 500′ travels upward and outward from axisL along a second axis A2 toward optical detector 144′. Reflectivesurface 500′ may produce a specular reflection with the reflected lighttraveling along a single axis A2, as shown in FIG. 19 , or a diffusereflection with the reflected light traveling in many differentdirections. Reflective surface 500′ may be a shiny, mirrored, orotherwise reflective surface. Reflective surface 500′ may be shaped andoriented to direct the reflected light toward optical detector 144′. Forexample, in FIG. 19 , the reflective surface 500′ is flat and is angledabout 10 degrees relative to a horizontal plane to direct the reflectedlight toward optical detector 144′. The angled reflective surface 500′of FIG. 19 may also encourage drainage of any condensation (fuel oraqueous) that forms upon reflective surface 500′.

The illustrative optical monitor 104 c′ also includes at least oneprinted circuit board (PCB) 502′ that mechanically and electricallysupports light source 140′ and optical detector 144′. PCB 502′ may alsoallow light source 140′ and/or optical detector 144′ to communicate withcontroller 102 (FIG. 3 ). Light source 140′ and optical detector 144′are illustratively coupled to the same PCB 502′, but it is also withinthe scope of the present disclosure to use distinct PCBs.

The illustrative optical monitor 104 c′ further includes a cover 510′,an upper housing 512′, and a lower housing 514′. Lower housing 514′ maybe removably coupled to upper housing 512′, such as using a snapconnection 515′, a threaded connection, or another removable connection.

Upper housing 512′ contains light source 140′, optical detector 144′,and circuit board 502′. Upper housing 512′ may be hermetically sealed toseparate and protect its contents from the potentially corrosiveenvironment in fuel delivery system 10 (FIG. 2 ). However, upper housing512′ may be at least partially or entirely transparent to permit thepassage of light, as discussed further below.

Lower housing 514′ contains target material 142′ and reflective surface500′. Reflective surface 500′ may be formed directly upon lower housing514′ (e.g., a reflective coating) or may be formed on a separatecomponent (e.g., a reflective panel) that is coupled to lower housing514′. In the illustrated embodiment of FIG. 19 , reflective surface 500′is located on bottom wall 516′ of lower housing 514′. Unlike thecontents of upper housing 512′, which are separated from the vapors infuel delivery system 10, the contents of lower housing 514′,particularly target material 142′, are exposed to the vapors in fueldelivery system 10. The illustrative lower housing 514′ has bottom wall516′ with a plurality of bottom openings 517′ and a side wall 518′ witha plurality of side openings 519′ to encourage the vapors in fueldelivery system 10 to enter lower housing 514′ and interact with targetmaterial 142′. Openings 517′, 519′ may vary in shape, size, andlocation. In general, lower housing 514′ should be designed to besufficiently solid to support and protect its contents while beingsufficiently open to expose its contents to the vapors in fuel deliverysystem 10. For example, the bottom openings 517′ may be concentratedbeneath target material 142′. Also, the side openings 519′ adjacent totarget material 142′ may be relatively small, whereas the side openings519′ opposite from target material 142′ may be relatively large.

In use, and as shown in FIG. 19 , light source 140′ directs a beam oflight along the first axis A₁, through the transparent upper housing512′, and toward target material 142′. The L-shaped configuration oftarget material 142′ may block any direct light pathways between lightsource 140′ and reflective surface 500′ to ensure that all of the lightfrom light source 140′ encounters target material 142′ before reachingreflective surface 500′. The light that is able to pass through thepores 143′ of target material 142′ continues to reflective surface 500′,which then reflects the light along the second axis A2, back through thetransparent upper housing 512′, and to optical detector 144′. Opticaldetector 144′ may signal a corrosive environment in fuel delivery system10 when the transmitted light intensity through the corroding targetmaterial 142′ reaches an undesirable level or changes at an undesirablerate, for example. After use, lower housing 514′ may be detached (e.g.,unsnapped) from upper housing 512′ to facilitate removal and replacementof the corroded target material 142′ and/or reflective surface 500′without disturbing the contents of upper housing 512′.

Optical monitor 104 c′ may be configured to detect one or more errors.If the light intensity detected by detector 144′ is too high (e.g., ator near 100%), optical monitor 104 c′ may issue a “Target MaterialError” to inform the operator that target material 142′ may be missingor damaged. To avoid false alarms caused by exposure to ambient light,such as when opening turbine sump 32 (FIG. 2 ), optical monitor 104 c′may only issue the “Target Material Error” when the high light intensityis detected for a predetermined period of time (e.g., 1 hour or more).On the other hand, if the light intensity detected by detector 144′ istoo low (e.g., at or near 0%), optical monitor 104 c′ may issue a “Lightor Reflector Error” to inform the operator that light source 140′ and/orreflective surface 500′ may be missing or damaged. In this scenario, theentire lower housing 514′, including reflective surface 500′, may bemissing or damaged.

Optical monitor 104 c′ may be combined with one or more other monitorsof the present disclosure. For example, in the illustrated embodiment ofFIG. 16 , PCB 502′ of optical monitor 104 c′ also supports a humiditysensor 520′, which passes through upper housing 512′ for exposure to thevapors in fuel delivery system 10 (FIG. 2 ). PCB 502′ may also support atemperature sensor (not shown), which may be used to compensate for anytemperature-related fluctuations in the performance of light source 140′and/or optical detector 144′.

In still yet another embodiment, monitor 104 collects spectroscopic dataindicative of a corrosive environment in fuel delivery system 10. Anexemplary spectrometer (not shown) operates by subjecting a liquid orvapor sample from fuel delivery system 10 to an energy source andmeasuring the radiative energy as a function of its wavelength and/orfrequency. Suitable spectrometers include, for example, infrared (IR)electromagnetic spectrometers, ultraviolet (UV) electromagneticspectrometers, gas chromatography-mass spectrometers (GC-MS), andnuclear magnetic resonance (NMR) spectrometers. Suitable spectrometersmay detect absorption from a ground state to an excited state, and/orfluorescence from the excited state to the ground state. Thespectroscopic data may be represented by a spectrum showing theradiative energy as a function of wavelength and/or frequency. It iswithin the scope of the present disclosure that the spectrum may beedited to hone in on certain impurites in the sample, such as acetateand acetic acid, which may cause corrosion in fuel delivery system 10,as well as sulfuric acid, which may cause odors in fuel delivery system10. As the impurities develop in fuel delivery system 10, peakscorresponding to the impurities would form and/or grow on the spectrum.The spectrometer may share the collected data with controller 102 (FIG.3 ) to signal a corrosive environment in fuel delivery system 10 whenthe impurity level reaches an undesirable level or changes at anundesirable rate, for example.

In still yet another embodiment, monitor 104 collects microbial dataindicative of a corrosive environment in fuel delivery system 10. Anexemplary microbial detector (not shown) operates by exposing a liquidor vapor sample from fuel delivery system 10 to a fluorogenic enzymesubstrate, incubating the sample and allowing any bacteria in the sampleto cleave the enzyme substrate, and measuring fluorescence produced bythe cleaved enzyme substrate. The concentration of the fluorescentproduct may be directly related to the concentration of acetic acidproducing bacteria (e.g., Acetobacter, Gluconobacter, Gluconacetobacter)in the sample. Suitable microbial detectors are commercially availablefrom Mycometer, Inc. of Tampa, Fla. The microbial detector may share thecollected data with controller 102 (FIG. 3 ) to signal a corrosiveenvironment in fuel delivery system 10 when the fluorescent productconcentration reaches an undesirable level or changes at an undesirablerate, for example.

To minimize the impact of other variables in monitor 104, a controlsample may be provided in combination with the test sample. For example,monitor 104 c of FIG. 6 may include a non-corrosive control material forcomparison with the corrosive target material 142. This comparison wouldminimize the impact of other variables in monitor 104 c, such asdecreasing output from light source 140 over time.

As discussed above, control system 100 of FIG. 3 includes a remediationsystem 108 capable of taking at least one corrective action to remediatethe corrosive environment in fuel delivery system 10. Controller 102 mayactivate remediation system 108 periodically (e.g., hourly, daily) in apreventative manner. Alternatively or additionally, controller 102 mayactivate remediation system 108 when the corrosive environment isdetected by monitor 104. Various embodiments of remediation system 108are described below with reference to FIG. 2 .

In a first embodiment, remediation system 108 is configured to ventilateturbine sump 32 of fuel delivery system 10. In the illustratedembodiment of FIG. 2 , remediation system 108 includes a firstventilation passageway 160 and a second ventilation or siphon passageway170.

The first ventilation passageway 160 illustratively includes an inlet162 in communication with the surrounding atmosphere and an outlet 164in communication with the upper vapor space (i.e., top) of turbine sump32. In FIG. 2 , the first ventilation passageway 160 is positioned inlid 38 of turbine sump 32, but this position may vary. A control valve166 (e.g., bulkhead-style vacuum breaker, check valve) may be providedalong the first ventilation passageway 160. Control valve 166 may bebiased closed and opened when a sufficient vacuum develops in turbinesump 32, which allows air from the surrounding atmosphere to enterturbine sump 32 through the first ventilation passageway 160.

The second ventilation or siphon passageway 170 is illustrativelycoupled to a siphon port 26 of pump 20 and includes an inlet 172positioned in the lower vapor space (i.e., middle) of turbine sump 32and an outlet 174 positioned in storage tank 16. A control valve 176(e.g., automated valve, flow orifice, check valve, or combinationthereof) may be provided in communication with controller 102 (FIG. 3 )to selectively open and close the second ventilation passageway 170.Other features of the second ventilation passageway 170 not shown inFIG. 2 may include a restrictor, a filter, and/or one or more pressuresensors.

When pump 20 is active (i.e., turned on) to dispense fuel product 14,pump 20 generates a vacuum at siphon port 26. The vacuum from pump 20draws vapor (e.g., fuel/air mixture) from turbine sump 32, directs thevapor to the manifold of pump 20 where it mixes with the circulatingliquid fuel flow, and then discharges the vapor into storage tank 16through the second ventilation passageway 170. As the vacuum in turbinesump 32 increases, control valve 166 may also open to draw fresh airfrom the surrounding atmosphere and into turbine sump 32 through thefirst ventilation passageway 160. When pump 20 is inactive (i.e., turnedoff), controller 102 (FIG. 3 ) may close control valve 176 to preventback-flow through the second ventilation passageway 170. Additionalinformation regarding the second ventilation passageway 170 is disclosedin U.S. Pat. No. 7,051,579, the disclosure of which is expresslyincorporated herein by reference in its entirety.

The vapor pressure in turbine sump 32 and/or storage tank 16 may bemonitored using the one or more pressure sensors (not shown) andcontrolled. To prevent over-pressurization of storage tank 16, forexample, the vapor flow into storage tank 16 through the secondventilation passageway 170 may be controlled. More specifically, theamount and flow rate of vapor pulled into storage tank 16 through thesecond ventilation passageway 170 may be limited to be less than theamount and flow rate of fuel product 14 dispensed from storage tank 16.In one embodiment, control valve 176 may be used to control the vaporflow through the second ventilation passageway 170 by opening the secondventilation passageway 170 for limited durations and closing the secondventilation passageway 170 when the pressure sensor detects an elevatedpressure in storage tank 16. In another embodiment, the restrictor (notshown) may be used to limit the vapor flow rate through the secondventilation passageway 170 to a level that will avoid an elevatedpressure in storage tank 16.

Other embodiments of the first ventilation passageway 160 are alsocontemplated. In a first example, the first ventilation passageway 160may be located in the interstitial space between a primary pipe and asecondary pipe (e.g., XP Flexible Piping available from Franklin FuelingSystems Inc. of Madison, Wis.) using a suitable valve (e.g., APT™ brandtest boot valve stems available from Franklin Fueling Systems Inc. ofMadison, Wis.). In a second example, the first ventilation passageway160 may be a dedicated fresh air line into turbine sump 32. In a thirdexample, the first ventilation passageway 160 may be incorporated into apressure/vacuum (PV) valve system. Traditional PV valve systemscommunicate with storage tank 16 and the surrounding atmosphere to helpmaintain proper pressure differentials therebetween. One such PV valvesystem is disclosed in U.S. Pat. No. 8,141,577, the disclosure of whichis expressly incorporated herein by reference in its entirety. In oneembodiment, the PV valve system may be modified to pull fresh airthrough turbine sump 32 on its way into storage tank 16 when theatmospheric pressure exceeds the ullage pressure by a predeterminedpressure differential (i.e., when a sufficient vacuum exists in storagetank 16). In another embodiment, the PV valve system may be modified toinclude a pair of tubes (e.g., coaxial tubes) in communication with thesurrounding atmosphere, wherein one of the tubes communicates withstorage tank 16 to serve as a traditional PV vent when the ullagepressure exceeds the atmospheric pressure by a predetermined pressuredifferential, and another of the tubes communicates with turbine sump 32to introduce fresh air into turbine sump 32.

Other embodiments of the second ventilation passageway 170 are alsocontemplated. In a first example, instead of venting the fuel/airmixture from turbine sump 32 into storage tank 16 as shown in FIG. 2 ,the mixture may be directed through a filter and then released into theatmosphere. In a second example, instead of using siphon port 26 as thevacuum source for the second ventilation passageway 170 as shown in FIG.2 , the vacuum source may be an existing vacuum pump in fuel deliverysystem 10 (e.g., 9000 Mini-Jet available from Franklin Fueling SystemsInc. of Madison, Wis.), a supplemental and stand-alone vacuum pump, or avacuum created by displaced fuel in storage tank 16 and/or fuel deliveryline 18. In one embodiment, and as discussed above, the secondventilation passageway 170 may be incorporated into the PV valve systemto pull fresh air through turbine sump 32 and then into storage tank 16when fuel is displaced from storage tank 16. In another embodiment, thesecond ventilation passageway 170 may communicate with an in-line siphonport on fuel delivery line 18 to pull air from turbine sump 32 when fuelis displaced along fuel delivery line 18.

In a second embodiment, remediation system 108 is configured toirradiate bacteria in turbine sump 32 of fuel delivery system 10. In theillustrated embodiment of FIG. 2 , a first radiation source 180 ispositioned on an outer wall of turbine sump 32, and a second radiationsource 180′ is positioned in the ullage of storage tank 16. Exemplaryradiation sources 180, 180′ include ultraviolet-C (UV-C) light sources.When activated by controller 102 (FIG. 3 ), radiation sources 180, 180′may irradiate and destroy any bacteria in turbine sump 32 and/or storagetank 16, especially acetic acid producing bacteria (e.g., Acetobacter,Gluconobacter, Gluconacetobacter).

In a third embodiment, remediation system 108 is configured to filterwater from fuel product 14. An exemplary water filtration system 200 isshown in FIG. 11 and is located together with pump 20 in turbine sump 32above storage tank 16 (FIG. 1 ). The illustrative water filtrationsystem 200 includes a fuel inlet passageway 202 coupled to port 27 ofpump 20, a water filter 204, a fuel return passageway 206 from the upperend of water filter 204, and a water removal passageway 208 from thelower end of water filter 204. The port 27 of pump 20 may be locatedupstream of leak detector 34 and its associated check valve (not shown)such that the water filtration system 200 avoids interfering with leakdetector 34.

Water filter 204 is configured to separate water, including emulsifiedwater and free water, from fuel product 14. Water filter 204 may also beconfigured to separate other impurities from fuel product 14. Waterfilter 204 may operate by coalescing the water into relatively heavydroplets that separate from the relatively light fuel product 14 andsettle at the lower end of water filter 204. Incoming fuel pressuredrives fuel radially outwardly through the sidewall of filter element207 (FIG. 15 ), which is made from a porous filter substrate adapted toallow fuel to pass therethrough while preventing water passagetherethrough. Any water that is separated from the fuel is drivendownwardly through the bottom of filter element 207, which is made froma porous filter substrate that allows the passage of water therethrough.The separated water then falls by gravity to the bottom of the filterhousing. Exemplary water filters 204 including filter element 207 areavailable from DieselPure Inc. Such water filters 204 may reduce thewater content of fuel product 14 to 200 ppm or less, according to theSAE J1488 ver.2010 test method.

The illustrative water filtration system 200 also includes one or moreinlet valves 203 to selectively open and close the fuel inlet passageway202 and one or more drain valves 209 to selectively open and close thewater removal passageway 208. In certain embodiments, valves 203, 209are solenoid valves that are controlled through controller 102. In otherembodiments, valves 203, 209 are manual valves that are manuallycontrolled by a user. In the embodiment of FIGS. 14-15 , inlet solenoidvalve 203 is provided downstream of strainer 205, which includes a meshscreen to protect valve 203 from exposure to solid sediment. A furthermanual ball valve 203′ is provided downstream of solenoid valve 203 formanual on/off control of the illustrated filtration system 200′, thedetails of which are further discussed below.

In operation, water filtration system 200 circulates fuel product 14through water filter 204. Water filtration system 200 may operate at arate of approximately 15 to 20 gallons per minute (GPM), for example.When pump 20 operates with inlet valve 203 open, pump 20 directs some orall of fuel product 14 from storage tank 16, through port 27 of pump 20,through the open fuel inlet passageway 202, and through water filter204. If a customer is operating dispenser 12 (FIG. 1 ) during operationof water filtration system 200, pump 20 may direct a portion of the fuelproduct 14 to dispenser 12 via the delivery line 18 (FIG. 1 ) andanother portion of the fuel product 14 to water filter 204 via the fuelinlet passageway 202. It is also within the scope of the presentdisclosure that the operation of water filtration system 200 may beinterrupted during operation of dispenser 12 by temporarily closinginlet valve(s) 203 and/or 203′ to water filter 204. As shownschematically in FIG. 14 , water filter 204 may produce a clean orfiltered fuel product 14 near the upper end of water filter 204 and aseparated water product, which may be a water/oil mixture, near thelower end of water filter 204. Alternatively, water filter 204A shown inFIGS. 21 and 22 may utilize water/oil separation to product a clean orfiltered fuel product 14, as described further below. For purposes ofthe present disclosure, “water filter 204” can interchangeably refer towater filter 204 shown in FIGS. 14 and 15 and described in detailherein, or to water filter 204A shown in FIGS. 21 and 22 and describedin detail herein. As used herein, “oil” may refer to oil and oil-basedproducts including motor fuel, such as gasoline and diesel.

The clean or filtered fuel product 14 that is discharged by water filter204, such as rising to the upper end of water filter 204, may bereturned continuously to storage tank 16 via the fuel return passageway206. The filtered fuel product 14 may be returned to storage tank 16 ina dispersed and/or forceful manner that promotes circulation in storagetank 16, which prevents debris from settling in storage tank 16 andpromotes filtration of such debris. By returning the filtered fuelproduct 14 to storage tank 16, water filtration system 200 may reducethe presence of water and avoid formation of a corrosive environment infuel delivery system 10 (FIG. 1 ), including storage tank 16 and/or sump32 of fuel delivery system 10. Water filtration system 200 may bedistinguished from an in-line system that delivers a filtered fuelproduct to dispenser 12 (FIG. 1 ) solely to protect a consumer'svehicle.

The separated water product that is discharged by water filter 204, suchas by settling at the lower end of water filter 204, may be drained viathe water removal passageway 208 when drain valve 209 is open. Theseparated water product may be directed out of turbine sump 32 and abovegrade for continuous removal, as shown in FIG. 11 . Alternatively, theseparated water product may be directed via passageway 208 to a storagetank 210 inside turbine sump 32 for batch removal when necessary, asshown in FIGS. 12, 14 and 22 . If the separated water product is awater/oil mixture, the separated water product may be subjected tofurther processing to remove any oil from the remaining water. Forexample, a selective absorbent, such as the Smart Sponge® available fromAbTech Industries Inc., may be used to absorb and remove any oil fromthe remaining water.

Referring to FIG. 14 , storage tank 210 further includes a vent line 236operable to vent the headspace above the separated water product as thelevel within tank 210 increases. In an exemplary embodiment, vent line236 may be routed to the headspace above fuel product 14 withinunderground storage tank 16, such that any treatment or capture of thevapor within tank 210 may be routed through existing infrastructure usedfor treatment/capture of fuel vapor within tank 16. Alternatively, tank210 may be vented to a dedicated space as required or desired for aparticular application.

The illustrative water filtration systems 200, 200′ of FIGS. 11, 12, 14and 15 include a high-level water sensor 220 and a low-level watersensor 222 operably connected to water filter 204. The water sensors 220and 222 may be capacitance sensors capable of distinguishing fuelproduct 14 from water. The high-level water sensor 220 may be locatedbeneath the entry into fuel return passageway 206 to prevent water fromentering fuel return passageway 206. The illustrative water filtrationsystem 200 of FIG. 12 further includes a high-level water sensor 224 instorage tank 210. The high-level water sensor 224 may be an opticalsensor capable of distinguishing the separated water product from air.Sensors 220, 222, and 224 may be low-power devices suitable foroperation in turbine sump 32. In one exemplary embodiment, filter 204may have a water capacity of about 2.75 liters (0.726 gallons) betweenthe levels of sensors 220, 222.

Turning to FIG. 14 , water filtration system 200′ is shown. Waterfiltration system 200′ is similar to filtration system 200 describedabove and includes several components and features in common with system200 as indicated by the use of common reference numbers between systems200, 200′. However, water filtration system 200′ further includeseductor 230 in fuel inlet passageway 202 which operates to effectcontinuous fuel filtration during operation of pump 20, while alsoallowing for normal operation of fuel dispenser 12 served by pump 20 asfurther described below.

As fuel is withdrawn from tank 16 by operation of pump 20, a portion ofthe fuel which would otherwise be delivered to dispenser 12 via deliveryline 18 is instead diverted to fuel inlet passageway 202. In anexemplary embodiment, this diverted flow may be less than 15gallons/minute, such as between 10 and 12 gallons/minute. This divertedflow of pressurized fuel passes through eductor 230, as shown in FIGS.14 and 15 , which is a venturi device having a constriction in thecross-sectional area of the eductor flow path. As the flow of fuelpasses through this construction, a negative pressure (i.e., a vacuum)is formed at vacuum port 232 (FIG. 15 ), which may be separate flow tubeterminating in an aperture formed in the sidewall of eductor 230downstream of the constriction.

Filtration uptake line 234 is connected to vacuum port 232 and extendsdownwardly into tank 16, such that filtration uptake line 234 draws fuelfrom the bottom of tank 16. In an exemplary embodiment, gap G₂ betweenthe inlet of line 234 and the bottom surface of tank 16 is zero ornear-zero, such that all or substantially all water or sediment whichmay be settled at the bottom of tank 16 is accessible to filtrationuptake line 234. For example, line 234 may be a rigid or semi-rigid tubewith an inlet having an angled surface formed, e.g., by a cut surfaceforming a 45-degree angle with the longitudinal axis of the tube. Thisangled surface forms a point at the inlet of line 234 which can belowered into abutting contact with the lower surface of tank 16, whilethe open passageway exposed by the angled surface allows the free flowof fuel into line 234. Other inlet configuration may also be used forline 234, including traditional inlet openings close to, but notabutting, the lower surface of the tank.

By contrast to the zero or near-zero gap G₂ for filtration uptake line234, a larger gap G₁ is formed between the intake of fuel uptake line 19and the bottom surface of tank 16. For example, the intake opening tosubmersible pump 24 (FIG. 1 ) may be about 4-6 inches above the lowersurface of tank 16. Where the pump is located above fuel product 14, theintake opening into fuel uptake line may instead be about 4-6 inchesabove the lower surface of tank 16. This elevation differentialreflected by gaps G₁ and G₂ ensures that any water or contaminated fuelsettled at the bottom of tank 16 will be taken up by filtration uptakeline 234 rather than fuel uptake line 19. At the same time, therelatively high elevation of the intake opening serving delivery line 18ensures that any accumulation of contaminated fuel will be safely withingap G₁, such that only clean fuel will be delivered to dispenser 12. Inthis way, filtration system 200′ simultaneously remediates contaminationand protects against uptake of any contaminated fuel that may exist intank 16, thereby providing “double protection” against delivery ofcontaminated fuel to dispenser 12.

The illustrative filtration system 200′ also achieves this dualmitigation/prevention functionality with low-maintenance operation, byusing eductor 230 to convert the operation of pump 20 into the motiveforce for the operation of system 200′. In particular, a single onlypump 20 used in conjunction with system 200′ both provides clean fuel todispenser(s) 12 via delivery line 18, while also ensuring that anyaccumulation of contaminated fuel at the bottom of tank 16 is remediatedby uptake into filtration line 234 and subsequent delivery to filter204. The lack of a requirement of extra pumping capacity lowers bothinitial cost and running costs. Moreover, the additional components ofsystem 200′, such as eductor 230, filter 204, valves 203, 209 and watertank 210, all require little to no regular maintenance.

Filtration system 200′ also achieves its dual mitigation/preventionfunction in an economically efficient manner by using an existing pumpto power the filtration process, while avoiding the need forlarge-capacity filters. As described in detail above, filtration system200′ is configured to operate in conjunction with the normal use of fueldelivery system 10 (FIG. 1 ), such that the filtration occurs wheneverdispensers 12 are used to fuel vehicles. This ensures that filtrationsystem 200′ will operate with a frequency commensurate with thefrequency of use of fuel delivery system 10. This high frequency ofoperation allows filter 204 to be specified with a relatively smallfiltration capacity for a given system size, while ensuring thatfiltration system 200′ retains sufficient overall capacity to mitigateeven substantial contamination. For example, a throughput of 10-12gallons/minute through filter 204 may be sufficient to treat all thefuel contained in a tank 16 sized to serve 6-8 fuel dispensers 12 (FIG.1 ) with each dispenser 12 capable of delivering 15-20 gallons of cleanfuel per minute. In this system sizing example, eductor 230 may be sizedto deliver 0.1-0.3 gallons per minute of fluid via filtration uptakeline 234 with a maximum vertical lift of 15 feet, using a flow throughfuel inlet passageway 202 of 10-12 gallons per minute at an inletpressure of about 30 PSIG (resulting in a pressure of at least 5 PSIG atthe outlet of eductor 230).

An alternative water filtration system 200A is shown in FIGS. 21 and 22. Water filtration system 200A is similar to filtration system 200′described above and includes several components and features in commonwith systems 200 and 200′, as indicated by the use of common referencenumbers between systems 200, 200′ and 200A. Moreover, common referencenumbers are used for common components of systems 200′ and 200A, andstructures of filtration system 200A have reference numbers whichcorrespond to similar or identical structures of filtration system 200′,except with “A” appended thereto as further described below. Filtrationsystems 200′ and 200A may be used interchangeably in connection withfuel delivery system 10 and its associated systems.

However, filtration system 200A includes filter 204A utilizing anoil/water separation tank 205A to accomplish the primary removal ofwater from fuel product 14, rather than a filter element 207 asdescribed above with respect to filtration system 200′. In addition, therouting of fuel flows and the use of eductor 230A in generating themotive force for fuel filtration contrasts with system 200′, asdescribed in further detail below.

Similar to system 200′, filtration system 200A uses a diverted flow offuel from submersible turbine pump 20 as the primary driver of fluidflows through eductor 230, such that pump 20 provides the primary motiveforce for filtration. In the illustrated embodiment of FIG. 22 , eductor230A receives the motive fuel flow from the outlet of pump 20, e.g.,along a discharge fluid passageway. However, it is contemplated thateductor 230 can receive a diverted flow on the suction side of pump 20,including from fuel uptake line 19, for example. The diverted fuel flowpasses through port 27 of pump 20, as shown in FIG. 21 , and throughinlet passageway 202, strainer 205 and inlet valve 203 in a similarfashion to system 200′. However, unlike system 200′, filtration system200A positions eductor 230 downstream of both valve 203, and the outletfuel flow from eductor 230A is delivered directly to fuel returnpassageway 206 and then to storage tank 16. This is in contrast to theflow of fluid discharged from eductor 230 described above, which directsboth the motive fuel flow from inlet passageway 202, and the filtrationflow from uptake line 234, to filter 204 (FIG. 15 ).

As best seen in FIG. 22 , filter 204A is functionally interposed betweeneductor 230A and fuel filtration uptake line 234A. As the motive fuelflow passes through eductor 230A from inlet passageway 202 to returnpassageway 206A, the vacuum created by eductor 230A is transmitted tothe interior of filter 204A via filter return passageway 216A whichextends from the vacuum port of eductor 230A to an aperture in the upperportion (e.g., the top wall) of filter 204A. This connection creates avacuum pressure within filter 204A, which draws a flow of fluid (e.g.,fuel or a fuel/water mixture) from the bottom of tank 16 via filtrationuptake line 234A. This filtration flow enters filter 204A at its topportion, but is delivered to the bottom portion of filter 204A via diptube 214A (FIG. 22 ).

In operation, filter 204A will operate in a steady state in which tank205A is always filled with fluid drawn from tank 16. New fluid receivedfrom uptake line 234A is deposited at the bottom of filter 204A via diptube 214A, and an equal flow of fluid is discharged from the top offilter 204A via return passageway 216. In an exemplary embodiment, theflow rate through filter 204A is slow enough, relative to the internalvolume of filter 204A, to allow for natural separation andstratification of water and fuel within the volume of filter 204A, suchthat any water contained in the incoming fuel remains at the bottom offilter 204A and only clean fuel is present at the top of filter 204A.

In an exemplary embodiment, the flow rate through filter 204A iscontrolled with a combination of vacuum pressure from eductor 230A andthe cross-sectional size of the channel defined by dip tube 214A. Thesetwo variables may be controlled to produce a nominal flow rate (i.e.,throughput) through filter 204A, as well as a fluid velocity through diptube 214A. In particular, the vacuum level produced by eductor 230A ispositively correlated with both flow rate and fluid velocity, while thecross-section of dip tube 214A is positively correlated with flow ratebut negatively correlated with fluid velocity. To preserve the abilityfor natural fluid stratification and avoid turbulence at the bottom offilter 204A, flow rate should be kept low enough to allow incoming fuelto remain coagulated as a volume of fuel separate from any surroundingwater, rather than separating out into smaller droplets that would needto re-coagulate before “floating” out of the water layer. For example,an exemplary fluid velocity which produces such favorable fluidmechanics for filter 204A may be as high as 1.0, 2.0, 3.0 or 4.0ft/second, such as about 3.3 ft/second.

In one exemplary arrangement, oil/water separation tank 205A has anominal volume of 1.1 gallons, dip tube 214A defines a fluid flowcannula with an internal diameter of 0.25 inches, and vacuum levelgenerated by eductor 230A is maintained between 12-15 inHg. Thisconfiguration produces a flow rate of about 0.50 gallons per minute(gpm) and an incoming fluid velocity (at the exit of dip tube 214A intothe lower portion of filter 204A) of about 3.27 ft/sec. In thisarrangement, throughput of filter 204A is maximized while preventingunfavorable fluid flow characteristics as described above. Moreover, ifvacuum is increased to 18 inHg, aeration of the incoming fuel can createunfavorable effects, such as foaming of diesel fuel.

Additional elements may be provided create operator control (or controlvia controller 102, shown in FIG. 3 ) over one or more constituentelements of the fluid velocity. For example, an adjustable orrestricting flow orifice, such a ball valve or flow orifice plate, maybe provided in the motive flow to eductor 230A. In an exemplaryembodiment, this restriction may be placed downstream of eductor 230A infuel return passageway 206A for example. This adjustable flow orificemay constrict the flow through passageway 206A, which establishes a backpressure on eductor 230A and thereby limits or defines the nominalvacuum pressure generated by eductor 230A. Another control element maybe a similar adjustable or restricting flow orifice placed in filtrationuptake line 234A, which limits the uptake flow rate to ensure thenominal flow volume and speed is achieved. In the above-describedexample of 0.50 gpm, a flow orifice diameter of 0.0938 inches in uptakeline 234A has been found to produce the target flow rate of 0.50 gpm andthe target flow speed of about 3.3 ft/sec when the vacuum pressure oneductor 230A is set to a target range of 12-15 inHg.

The size of filter 204A may be scaled up or down to accommodate anydesired filtration capacity, and the particular configuration offiltration system 200A can be modified in keeping with the principlesarticulated above. For example, increasing the cross-section of dip tube214A decreases fluid velocity, such that the nominal flow rate throughfiltration uptake line 234A may be increased without producing anunfavorable fluid velocity. Similarly, the nominal volume of tank 205Amay be decreased if no turbulence is experienced in the stratificationof the contained fluids, or may be increased in order to accommodate amodest level of turbulence.

If water is present in the fluid drawn from the bottom of storage tank16 through uptake line 234A (FIG. 21 ), the water will naturallyseparate from the fuel and settle to the bottom of filter 204A, wherethe water is collected and retained for later withdrawal (describedbelow). The clean fuel 14, which floats to the top of the stratifiedfluids within filter 204A, will be drawn back through eductor 230 viafilter return passageway 216A and allowed to mix with the motive flow offuel to be discharged to tank 16 via fuel return passageway 206A. Inthis way, filter return passageway 216A combines with fuel returnpassageway 206A to form the fuel return passageway which returnsfiltered fuel product from filter 204A to the storage tank.

If sufficient water accumulates within filter 204A, the water reacheshigh-level water sensor 220A (FIG. 22 ) exposed to the interior of tank205A and positioned above the lower portion of filter 204A. In theillustrated embodiment, high-level water sensor 22A is located on theupper portion of the filter 204A, at a height that results in a majorityof the fluid in the filter 204A being below sensor 220A. In someembodiments, 60%, 70%, 80% or 90% of the internal volume of filter 204Amay be below sensor 220A. This arrangement allows a significant amountof water to accumulate to avoid frequent draining procedures, while alsousing the remaining filter volume as a secure buffer of clean fuel abovethe water level to prevent accidental discharge of water or contaminatedfuel from filter 204A to storage tank 16.

When contacted with water, sensor 220A activates and sends a signal tocontroller 102 (FIG. 3 ), which may then activate an alarm or initial aremediation protocol, or take other corrective action as describedherein. For example, activation of water sensor 220A may issue anotification to prompt an operator to drain the water accumulated intank 205A, or may initiate a similarly automated water removal process.

FIG. 22 illustrates water removal passageway 208A, which is functionallyinterposed between filtration uptake line 234A and dip tube 214A. Toinitiate a water removal procedure either by a human operator or byoperation of controller 102 (FIG. 3 ), uptake valve 212A may first beclosed to prevent any further uptake of fuel 14 from tank 16. Wateroutlet valve 209A may then be opened, and a pump (not shown) attached towater removal passageway 208A may be activated to draw water from thebottom of filter 204A via dip tube 214A. Where the water withdrawal isdone by a human operator, a hand pump or manually operable electric pumpmay be used. Alternatively, an automated electric pump may be used bythe operator, or controlled by controller 102 (FIG. 3 ) to automaticallydrain the water as part of a corrective action protocol.

In an exemplary embodiment, check valve 218A may be provided in uptakeline 234 between tank 16 and uptake valve 212A, in order to provideadditional insurance against a backflow of water into tank 16 duringwater withdrawal. Check valve 218A also guards against any potentialsiphoning of water from filter 204A, which may be located physicallyabove tank 16, into tank 16 via dip tube 214A and filtration uptake line234A.

The water withdrawal process may be calibrated, either by a humanoperator or controller 102 (FIG. 3 ), to withdraw a predeterminedquantity of fluid upon initiation of a water removal protocol. Thepredetermined amount may be the volume of fluid calculated to existbelow water sensor 220A and within water filter 204A, for example.Optionally, inlet valve 203 may be closed during the water removalprocess, in order to prevent a competing suction pressure from eductor230. Alternatively, turbine pump 20 (FIG. 21 ) may be shut down andinlet valve 203 may be left open.

Turning now to FIG. 23 , filtration system 200B includes anotherseparator-type filter 204B and is otherwise similarly constructed tofiltration system 200A described above. Common reference numbers areused for common components of systems 200′, 200A and 200B, andstructures of filtration system 200B have reference numbers whichcorrespond to similar or identical structures of filtration systems 200′and 200A, except with “B” appended thereto as further described below.Filtration system 200B has all the same functions and features asfiltration system 200A described above, except as noted below.Filtration systems 200′, 200A and 200B may be used interchangeably inconnection with fuel delivery system 10 and its associated systems.

However, filter 204B of filtration system 200B includes sensor valveassembly 244, shown in FIGS. 24B-27 , which can be used in lieu of (orin addition to) high-level water sensor 220A (FIG. 22 ) to sense thepresence of water near the top of tank 205B and, in conjunction withsensor 242 (FIG. 24B), issue a signal or alert indicative of thishigh-water condition.

As best seen in FIG. 23 , the components of filtration system 200B aresized and configured to fit within sump 32, together with a typical setof existing components including turbine pump 22, delivery lines 18 andassociated shutoff valves and ancillary structures. In the illustrativeembodiment of FIGS. 24A and 24B, mounting bracket 240 is provided toprovide structural support for tank 205B and associated structures fromthe flow lines between inlet passageway 202B and return passageway 206B.

Like filtration systems 200, 200′ and 200A described above, filtrationsystem 200B may also be applied to other sumps or parts of fuel deliverysystem 10, such as dispenser sump 30 (FIG. 1 ). Also similar to systems200′ and 200A, system 200B uses a diverted flow of fuel from submersibleturbine pump 20 as the primary driver of fluid flows through eductor230, via inlet passageway 202B and strainer 205 (FIG. 24A), such thatpump 20 provides the primary motive force for filtration.

Fuel flows downstream to fuel return passageway 206B to return to theunderground storage tank 16 (FIG. 24A), passing eductor 230 to createvacuum pressure in filter return passageway 216B, which in turntransmits the vacuum pressure to the interior of tank 205B via valveassembly 244 (as further described below). This vacuum pressure alsowithin tank 205B is sufficient to draw fuel from UST 16 via filtrationuptake line 234B, which extends to the bottom of UST 16 as seen in FIG.24A and also described in detail herein with respect to other filtrationsystem configurations. The fuel drawn through uptake line 234B providesa slow and steady flow into the bottom of tank 205B via dip tube 214B,also described in greater detail with respect to filtration system 200A.During steady-state operation, the vacuum in return passageway 216Bdraws fuel back to the primary return flow through fuel returnpassageway 206B. In the illustrated embodiment of FIGS. 24A and 24B,strainer 205 is provided between valve assembly 244 and eductor 230.

Turning now to FIG. 25 , filter 204B is shown partially filled withwater W and, during steady-state operation, the remainder of tank 205Bis filled with fuel floating above water W. In this configuration, float248 resides at the bottom of the interior cavity 252 of sensor valvebody 246 of sensor assembly 244, retained by snap ring 250. Fueldeposited into tank 205B via dip tube 214B rises to float on the heavierwater W, while any water contained in the deposited fuel stratifies toremain in water W. Because water W is well below float 248, pure fuel iscontinuously cycled through sensor valve assembly via ports 249 in valvebody 246. This pure fuel is then drawn into vacuum port 254 to bereturned to UST 16 via return passageway 216B (FIG. 24B).

During the steady-state, low-water operation depicted by FIG. 25 , avacuum is maintained throughout the components of water filtrationsystem 200B as described herein. This vacuum maintains a steady flow offuel through filter return passageway 216B via eductor 230, as shown inFIG. 24B. This flow is measured by flow sensor 242, which is in fluidcommunication with the suction port of eductor 230 and/or the interiorflow path defined by passageway 216B. Sensor 242 detects the presence(and, optionally, the rate) of fluid flow through the suction port ofeductor 230, and issues a signal (or a lack of a signal) indicative ofsuch fluid flow. This signal may be received by controller 102, forexample, or may simply be received by an operator via an indicator(light, siren, etc.).

In FIG. 26 , the level of water W has risen such that a portion ofsensor valve assembly 244 is submerged below the level of water W. Float248 has a density below that of water W, but above that of thehydrocarbon fuel stratified above water W as described above. Details ofan exemplary float 248 can be found in U.S. Pat. No. 8,878,682, entitledMETHOD AND APPARATUS FOR DETECTION OF PHASE SEPARATION IN STORAGE TANKSUSING A FLOAT SENSOR and filed Oct. 16, 2009, the entire disclosure ofwhich is hereby expressly incorporated herein by reference. As the levelof water W rises to engage float 248, float 248 rises within interiorcavity 252, eventually approaching the top wall of cavity 252 and port254. When float 248 get near enough to port 254, the concentration ofvacuum pressure at port 254 draws float 248 into contact with the topwall of cavity 252 as illustrated in FIG. 26 , shutting off (orsubstantially reducing) the flow of fluid. Because port 254 becomesblocked as a result of a high water level, shutting off the flow offluid from filter 204B prevents any of water W from reentering UST 16.

The ceasing of fluid flow through passageway 216B also stops fluid flowat the vacuum port of eductor 230. In addition, the flow of fluid mayreduce before ceasing completely. Sensor 242 detects the reductionand/or cessation of fluid flow, and issues a signal (or a lack of asignal) indicative of cessation of flow or of a reduction of flow belowa predetermined threshold nominal value. Controller 102 may issue analert and/or initiate remediation when sensor 242 indicates the highlevel of water W shown in FIG. 26 . As described in detail above withrespect to filtration system 200A, remediation may include draining ofwater W. To facilitate such draining, water filtration system 200B maybe equipped with the same water removal passageway 208 and associatedstructures found in filtration system 200A, as shown in FIG. 22 anddescribed in detail above. When water W is removed from tank 205B, float248 falls away from port 254 toward its bottom-seated position shown inFIG. 25 , once again allowing fluid to flow through the vacuum port ofeductor 230.

As noted above, water filter 204B may be located within a sump (e.g.,sump 32 shown in FIG. 23 ) and therefore near or above grade. Becausewater W may be allowed to accumulate within tank 205B, below-freezingweather has the potential to create ice within tank 205B. To addressthis potential in cold-weather installations, a temperature probe may beinstalled within or on the outside wall of tank 205B and configured toissue a signal to controller 102 or a system operator. When thetemperature probe indicates temperatures near, at, or below freezing,the operator or controller 102 may initiate a flow of fuel from UST 16through filter 204B, as described herein. Because the UST 16 is locatedunderground and well below grade, the incoming fuel is reliably abovefreezing and can be used to maintain the internal temperature of tank205B above freezing. This incoming flow may be maintained until thetemperature probe reaches a threshold above-freezing temperature,regardless of whether controller 102 is calling for fuel flow forfiltration purposes. Although this temperature-control system and methodare described with respect to filtration system 200B, the same systemmay also be applied in the same way to other filtration systems made inaccordance with the present disclosure, including systems 200, 200′ and200A.

Controller 102 (FIG. 3 ), or a human operator, may also use inlet valve203 to selectively activate or deactivate the fuel filtration processenabled by filtration systems 200A or 200B (or, alternatively, systems200 or 200′, it being understood that systems 200, 200′, 200A and 200Bmay be used interchangeably as noted herein). For example, controller102 may be programmed with a pre-determined schedule for fuelfiltration, and may open valve 203 to initiate a filtration cycle. Aftera predetermined amount of time during which the filtration cycle isactive and filtration is occurring as described above, controller 102may close valve 203 to stop the filtration cycle. After a predeterminedamount of time during which the filtration cycle is not active, a newcycle may begin. Alternatively, in some embodiments, valve 203 may beomitted or left open, such that fuel filtration occurs any time pump 20is active.

The use of the separator-type filters 204A, 204B allow filtrationsystems 200A, 200B to be virtually maintenance free, with the onlyregular maintenance task being the periodic removal of accumulated waterfrom filter 204A, 204B. Even this maintenance task may be automated asnoted above. In contrast to filtration system 200′, which uses asubstrate-type filter 207 as described in detail above, filtrationsystems 200A, 200B have no substrate filters which would requirereplacement or service.

The separator-type filters 204A, 204B may also be sized to fit existingor newly-installed sumps, such as turbine sump 32 of fuel deliverysystem 10 (FIG. 1 ). As noted above, a system designer has flexibilityin sizing the volume of filters 204A, 204B by controlling the flow rateof fluid to be filtered. Therefore, where there is a requirement for afiltration system to accommodate a small space within a sump, filters204A, 204B can be sized accordingly and the nominal filtration flow rateper can be set at an appropriate percentage of the filter volume asdescribed in detail above.

However, it is contemplated that a filter substrate, such as filter 207,or any other coalescing filter element, particulate filter element, or acombination thereof may be used inside filters 204A, 204B, as requiredor desired for a particular application.

As discussed herein, filtration systems 200, 200′, 200A and 200B utilizesubmersible pump 20, already existing as a component of fuel deliverysystem 10, as a motive fuel flow source to power a vacuum generatingdevice, illustrated with respect to the various embodiments as eductor230. Although the illustrative filtration systems 200′, 200A, 200B useeductor 230 to draw the contaminated fuel from the bottom of tank 16,other equipment may be used to perform this operation, such as anothertype of venturi device or a supplemental pump (in addition to pump 20).For example, a flow from the pump 20, including a primary and/ordiverted flow, may be used to drive an impeller which drives a separatepump for filtration, similar to the operation of a turbocharger systemof an internal combustion engine, which uses exhaust gases to power animpeller. The dedicated filtration pump powered by the flow of theprimary pump may then be used in place of eductor 230 to drivefiltration flows as described herein.

Yet another alternative is to use a dedicated, electrically powered pumpfor filtration flows. This dedicated pump may be used in place ofeductor 230 or 230A as shown in FIGS. 15 and 22 , for example. In thisconfiguration of filtration system 200, 200′, 200A or 200B, fuel returnpassageway 206, 206A or 206B is used only for return of filtered fuelflows, with no need for a separate motive flow of fuel as describedherein with respect to venturi-based systems. The dedicated filtrationpump may have a low-flow configuration sufficient for only thefiltration flow desired for the throughput of filter 204, 204A or 204B.

In still another alternative arrangement, pump 20 may be configured as adiaphragm-type pump, in which a primary stroke of the pump is used fordelivery of fuel to dispenser 12 via delivery line 18 (FIG. 1 ), whilethe reverse stroke can be used to drive filtration flows as describedherein. In this configuration, of filtration system 200, 200′, 200A or200B eductor 230 is omitted. If the flows resulting from the reversestroke of the diaphragm pump 20 are commensurate with the desiredfiltration flows through filter 204, 204A or 204B, then fuel returnpassageway 206, 206A or 206B is again used only for filtration flowswith no separate excess or motive flow. If the flows from the reversestroke of diaphragm pump 20 are higher than the desired flows throughfilter 204, 204A or 204B, then fuel return passageway 206, 206A or 206Bmay be also be sized to discharge excess flows back to tank 16.

Referring next to FIG. 13 , an exemplary method 300 is disclosed foroperating water filtration systems 200, 200′, 200A, 200B. Method 300 maybe performed using controller 102 (FIG. 3 ). Method 300 is describedbelow with reference to the illustrative water filtration system 200 ofFIG. 12 , though the disclosed method is also applicable to systems200′, 200A and 200B.

In step 302 of method 300, controller 102 determines whether apredetermined start time has been reached. The start time may occur at adesired time, preferably outside of high-demand fuel dispensing hours(e.g., 4:30 to 7:30 AM), and with a desired frequency. For example, thestart time may occur daily at about 8:00 PM. When the start time of step302 is reached, method 300 continues to step 304. It is also within thescope of the present disclosure that method 300 may be initiated basedon an input from one or more monitors 104 (FIG. 3 ). It is furtherwithin the scope of the present disclosure that method 300 may beinitiated only when a certain minimum level of fuel product 14 ispresent in storage tank 16, such as about 20 to 30 inches of fuelproduct 14, more specifically about 24 inches of fuel product 14.

In step 304 of method 300, controller 102 operates water filter 204 tofilter fuel product 14. As discussed above, this filtering step 304 mayinvolve opening inlet valve 203 of fuel inlet passageway 202 andactivating pump 20. After passing through water filter 204, the filteredfuel product 14 may be returned continuously to storage tank 16 via fuelreturn passageway 206.

In step 306 of method 300, controller 102 determines whether apredetermined cycle time has expired. The cycle time may vary. Forexample, the cycle time may be about 1-10 hours, more specifically about7-9 hours, and more specifically about 8 hours. If the cycle time hasexpired, method 300 continues to step 307, in which controller 102closes inlet valve 203 of fuel inlet passageway 202 to water filter 204and resets the cycle time before returning to step 302 to await a newstart time. If the cycle time has not yet expired, method 300 continuesto step 308.

In step 308 of method 300, controller 102 determines whether a waterlevel in water filter 204 is too high. Step 308 may involvecommunicating with the high-level water sensor 220 in water filter 204.If the high-level water sensor 220 detects water (i.e., activates),method 300 continues to steps 310 and 312. If the high-level watersensor 220 does not detect water (i.e., deactivates), method 300 skipssteps 310 and 312 and continues to step 314.

In step 310 of method 300, controller 102 drains the separated waterproduct from water filter 204. As discussed above, this draining step310 may involve opening drain valve 209 of water removal passageway 208.From step 310, method continues to step 312.

In step 312 of method 300, controller 102 determines whether a waterlevel in water filter 204 is sufficiently low. Step 312 may involvecommunicating with the low-level water sensor 222 in water filter 204.If the low-level water sensor 222 still detects water (i.e., activates),method 300 returns to step 310 to continue draining water filter 204.Once the low-level water sensor 222 no longer detects water (i.e.,deactivates), method 300 continues to step 314. Controller 102 mayinitiate an alarm if the draining step 310 is performed for apredetermined period of time without deactivating the low-level watersensor 222. Controller 102 may also initiate an alarm if a discrepancyexists between the high-level water sensor 220 and the low-level watersensor 222, specifically if the high-level water sensor 220 detectswater (i.e., activates) but the low-level water sensor 222 does notdetect water (i.e., deactivates).

In step 314 of method 300, controller 102 determines whether a waterlevel in storage tank 210 is too high. Step 314 may involvecommunicating with the high-level water sensor 224 in storage tank 210.Step 314 may also involve calculating the volume of water contained instorage tank 210 based on prior draining steps 310 from water filter204. This volume calculation may involve logging the number of drainingsteps 310 from water filter 204 triggered by the high water-level sensor220 and determining the known volume of water drained between sensors220 and 222 during each draining step 310. If the high-level watersensor 224 does not detect water (i.e., deactivates) or the calculatedwater volume inside storage tank 210 is lower than a predeterminedlimit, method 300 returns to step 304 to continue operating water filter204. If the high-level water sensor 224 detects water (i.e., activates)or the calculated water volume inside storage tank 210 reaches thepredetermined limit, method 300 continues to step 316.

In step 316 of method 300, controller 102 initiates an alarm or sendsanother communication requiring storage tank 210 to be emptied andreplaced. Controller 102 also closes inlet valve 203 of fuel inletpassageway 202 and resets the cycle time. After storage tank 210 isemptied and replaced, controller 102 returns to step 302 to await a newstart time.

In a fourth embodiment, remediation system 108 is configured to controlthe humidity in turbine sump 32 of fuel delivery system 10. In theillustrated embodiment of FIG. 2 , remediation system 108 includes adesiccant 400 (e.g., calcium chloride, silica gel) that is configured toadsorb water from the atmosphere in turbine sump 32. Desiccant 400 maybe removably coupled to turbine sump 32, such as being detachablysuspended from lid 38 of turbine sump 32. In this embodiment, monitor104″″ may be a humidity sensor that is configured to measure thehumidity in the vapor space of turbine sump 32. Monitor 104″″ may alsobe configured to measure the temperature in the vapor space of turbinesump 32. The humidity and/or temperature data may be communicated tocontroller 102 (FIG. 3 ). When the humidity level increases above apredetermined level (e.g., 40%), output 106 may instruct the operator toinspect turbine sump 32 and/or to replace desiccant 400.

The above-described embodiments of remediation system 108 may beprovided individually or in combination, as shown in FIG. 2 . Thus,remediation system 108 may be configured to ventilate turbine sump 32 offuel delivery system 10, irradiate bacteria in turbine sump 32 of fueldelivery system 10, operate water filtration system 200, and/or controlthe humidity in turbine sump 32 of fuel delivery system 10.

While this invention has been described as having exemplary designs, thepresent invention can be further modified within the spirit and scope ofthis disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

EXAMPLES 1. Example 1: Degradation of Transmitted Light Intensity inCorrosive Environment

Various plain steel samples were prepared as summarized in Table 1below. Each sample was cut into a 1-inch square.

TABLE 1 No. Description Dimensions 1 Fine wire mesh 60 × 60 mesh,0.0075″ wire diameter 2 Thick wire mesh 14 × 14 mesh, 0.035″ wirediameter 3 Perforated sheet 0.033″ hole diameter 4 Fine wire mesh 30 ×30 mesh, 0.012″ wire diameter 5 Perforated sheet 0.024″ hole diameter

The samples were placed in a sealed glass container together with a 5%acetic acid solution. The samples were suspended on a non-corrosive,stainless steel platform over the acetic acid solution for exposure tothe acetic acid vapor in the container. Select samples were removed fromthe container after about 23, 80, and 130 hours. Other samples werereserved as control samples.

Each sample was placed inside a holder and illuminated with a LED lightsource inside a tube to control light pollution. An ambient light sensorfrom ams AG was used to measure the intensity of the light passingthrough each sample. The results are presented in FIGS. 7-9 . FIG. 7includes photographs of the illuminated samples themselves. FIG. 8 is agraphical representation of the relative light intensity transmittedthrough each sample over time. FIG. 9 is a graphical representation ofthe normalized light intensity transmitted through each sample overtime, with an intensity of 1.00 assigned to each control sample. Asshown in FIGS. 7-9 , all of the samples exhibited increased corrosionand decreased light transmission over time. The fine wire mesh samples(Sample Nos. 1 and 4) exhibited the most significant corrosion overtime.

2. Example 2: Real-Time Degradation of Transmitted Light Intensity inCorrosive Environment

Sample No. 4 of Example 1 was placed inside a sealed plastic bagtogether with a paper towel that had been saturated with a 5% aceticacid solution. The sample was subjected to illumination testing in thesame manner as Example 1, except that the sample remained inside thesealed bag during testing. The results are presented in FIG. 10 , whichis a graphical representation of the actual light intensity transmittedthrough the sample over time. Like Example 1, the sample exhibitedincreased corrosion and decreased light transmission over time.

3. Example 3: Humidity Control with Desiccant

A turbine sump having a volume of 11.5 cubic feet and a stabletemperature between about 65° F. and 70° F. was humidified to about 95%using damp rags. The rags were then removed from the humidified turbinesump. A desiccant bag was placed inside the humidified turbine sump,which was then sealed closed. The desiccant bag contained 125 g ofcalcium chloride with a gelling agent to prevent formation of aqueouscalcium chloride.

The relative humidity and temperature in the turbine sump were measuredover time, as shown in FIG. 20 . After 1 day, the desiccant had adsorbedenough moisture to decrease the relative humidity to about 40%. After 3days, the desiccant had adsorbed enough moisture to decrease therelative humidity beneath about 20%. The relative humidity eventuallydecreased beneath 10%.

What is claimed is:
 1. A fuel delivery system comprising: a storage tankcontaining a fuel product; a sump; a pump having a fuel intake inletpositioned in the sump and a fuel intake outlet positioned in thestorage tank, the fuel intake inlet forming a first gap between a bottomof the storage tank and the fuel intake inlet; and a water filtrationsystem comprising: a water filter positioned in the sump and configuredto separate the fuel product into a filtered fuel product and aseparated water product; a filtration uptake line extending from afiltration uptake inlet in the storage tank to a filtration uptakeoutlet in the water filter, the filtration uptake line configured todraw a filtration flow of the fuel product into the water filter, thefiltration uptake inlet forming a second gap between the bottom of thestorage tank and the filtration uptake inlet, the first gap larger thanthe second gap, whereby contaminants settled at the bottom of thestorage tank flow into the filtration uptake line before the fuel uptakeline; a fuel return passageway having a filtered fuel inlet in the waterfilter and a filtered fuel outlet in fluid communication with thestorage tank to return the filtered fuel product to the storage tank;and a water removal passageway in fluid communication with the waterfilter to drain the separated water product from the water filter. 2.The fuel delivery system of claim 1, wherein the fuel inlet passagewayis coupled to the pump at a location upstream of a leak detector.
 3. Thefuel delivery system of claim 1, further comprising: an inlet valvepositioned along the fuel inlet passageway; and a controller that opensthe inlet valve at a predetermined start time outside of high-demandfuel dispensing hours.
 4. The fuel delivery system of claim 1, furthercomprising: a drain valve positioned along the water removal passageway;a high-level water sensor positioned in the water filter; and acontroller that opens the drain valve when the high-level water sensordetects water in the water filter.
 5. The fuel delivery system of claim4, further comprising a low-level water sensor positioned in the waterfilter, wherein the controller closes the drain valve when the low-levelwater sensor does not detect water in the water filter.
 6. The fueldelivery system of claim 4, wherein the high-level water sensor ispositioned beneath an entry into the fuel return passageway.
 7. The fueldelivery system of claim 1, wherein the water removal passageway extendsout of the sump to drain the separated water product continuously out ofthe sump.
 8. The fuel delivery system of claim 1, wherein the waterremoval passageway extends to a second storage tank positioned in thesump to drain the separated water product into the storage tank.
 9. Thefuel delivery system of claim 8, further comprising: a high-level watersensor positioned in the second storage tank; and a controller thatsends a communication requiring the second storage tank to be emptiedwhen the high-level water sensor detects water in the second storagetank.
 10. The fuel delivery system of claim 1, further comprising aselective absorbent in fluid communication with the water removalpassageway to remove oil from the separated water product.
 11. The fueldelivery system of claim 1, wherein the fuel return passageway returnsthe filtered fuel product to the storage tank in a manner that promotescirculation in the storage tank.
 12. A fuel delivery system comprising:a water filtration system comprising: a filter configured to separate afuel product into a filtered fuel product and a separated water product;an eductor configured to receive a motive flow of fuel from a fueldelivery pump; a vacuum port on the eductor configured to be operablyconnected to a source of contaminated fuel, the vacuum port configuredto respond to the motive flow of fuel by drawing a filtration flow offuel from the source of contaminated fuel, the eductor providing thefiltration flow of fuel to the filter.
 13. The fuel delivery system ofclaim 12, further comprising: a storage tank containing a fuel product;and a fuel dispenser; wherein the fuel delivery pump has a fuel uptakeline connected to the eductor and the dispenser, such that the fueldelivery pump is configured to discharge the fuel product to the eductorand a dispensing nozzle simultaneously.
 14. The fuel delivery system ofclaim 13, further comprising a sump, the fuel delivery pump having afirst portion positioned in the sump and a second portion positioned inthe storage tank.
 15. The fuel delivery system of claim 14, furthercomprising a filtration uptake line extending from the tank to thefilter, wherein: a first gap is formed between a bottom of the storagetank and an inlet to the fuel uptake line; and a second gap is formedbetween the bottom of the storage tank and an inlet to the filtrationuptake line, the first gap larger than the second gap, wherebycontaminants settled at the bottom of the storage tank flow into thefiltration uptake line before the fuel uptake line.
 16. The fueldelivery system of claim 12, wherein the filter comprises an oil/waterseparation tank.
 17. A fuel delivery system comprising: a storage tankcontaining a fuel product; a dispenser; a water filter; a fuel uptakeline extending from the storage tank to the dispenser to deliver adispenser flow of the fuel product to the dispenser; a filtration uptakeline extending from the storage tank to the water filter to draw afiltration flow of the fuel product to the water filter, the waterfilter being configured to separate the fuel product into a filteredfuel product and a separated water product; a fuel return passagewayextending from the water filter to the storage tank to return a filteredflow of the filtered fuel product to the storage tank; an eductor havinga first port receiving a portion of the dispenser flow, a second portreceiving the filtered flow, and a third port discharging both thedispenser flow and the filtered flow to the storage tank, the eductorcreating a vacuum in the water filter to power the filtration flow; anda water removal passageway in fluid communication with the water filterto drain the separated water product from the water filter.
 18. The fueldelivery system of claim 17, further comprising: a pump positioned alongthe fuel uptake line; and a motive-flow line receiving the portion ofthe dispenser flow, the eductor positioned along the motive-flow line.19. The fuel delivery system of claim 17, wherein an inlet to thefiltration uptake line is positioned closer to a bottom surface of thestorage tank than an inlet to the fuel uptake line.